The present invention relates to a mounting unit of a traction element drive that is constructed, in particular, as a chain drive that can be used in internal combustion engines. The traction element drive comprises a drive wheel and at least one driven wheel that are connected by a traction element, wherein a guide rail or a tensioning rail connected to a tensioning system is allocated to each section of the traction element.
From DE 39 09 458 A1, a mounting unit for a traction element drive is known that comprises a chain wheel holder as well as a chain guide element for the timing chain of an internal combustion engine. This mounting unit includes arc-shaped holders in which the chain wheels and the timing chain are loosely placed. A tensioning device allocated to the traction element drive is supported on the chain on the outside with a non-positive fit. Because the tensioning device is mounted biased in connection with the traction element drive, the mounting complexity increases, because, for example, influenced by the effect of the tensioning device, it is difficult to mount the chain wheels onto the associated shaft ends.
EP 0 848 139 A1 relates to a mounting unit in which the traction element wheels are inserted into holding pockets and are positioned by the traction element wrapping around these wheels and are fixed by a catch element of the holding device. The mounting unit includes an arc-shaped tensioning rail which is pressed upon, in the operating state, by a chain tensioner positioned on the engine block of the internal combustion engine. For the mounting, the tensioning rail is held by a catch element in a home position that generates a certain amount of biasing in the traction element.
In common, the mounting units described above are left in place after completion of the mounting on the internal combustion engine. With respect to the relatively high number of pieces in internal combustion engines and the decreasing cycle times due to advancing automation in the automotive industry, the mounting units in the individual components and functions are subject to a constant demand for improvement and adaptation to rising requirements.